CN105738215A - Novel method for testing geostress jointly by acoustic emission and differential strain - Google Patents
Novel method for testing geostress jointly by acoustic emission and differential strain Download PDFInfo
- Publication number
- CN105738215A CN105738215A CN201610131570.3A CN201610131570A CN105738215A CN 105738215 A CN105738215 A CN 105738215A CN 201610131570 A CN201610131570 A CN 201610131570A CN 105738215 A CN105738215 A CN 105738215A
- Authority
- CN
- China
- Prior art keywords
- acoustic emission
- strain
- differential strain
- differential
- testing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000012360 testing method Methods 0.000 title claims abstract description 63
- 238000000034 method Methods 0.000 title claims abstract description 36
- 239000011435 rock Substances 0.000 claims abstract description 34
- 239000000523 sample Substances 0.000 claims abstract description 20
- 238000012544 monitoring process Methods 0.000 claims abstract description 13
- 230000008569 process Effects 0.000 claims abstract description 11
- 230000000694 effects Effects 0.000 claims abstract description 10
- 238000002474 experimental method Methods 0.000 claims description 29
- 238000007906 compression Methods 0.000 claims description 9
- 230000006835 compression Effects 0.000 claims description 7
- 238000012806 monitoring device Methods 0.000 claims description 2
- 230000008859 change Effects 0.000 abstract description 8
- 239000003921 oil Substances 0.000 description 15
- 238000005259 measurement Methods 0.000 description 12
- 230000009471 action Effects 0.000 description 3
- 238000004458 analytical method Methods 0.000 description 3
- 238000011161 development Methods 0.000 description 3
- 238000005553 drilling Methods 0.000 description 3
- 239000010720 hydraulic oil Substances 0.000 description 3
- 238000007405 data analysis Methods 0.000 description 2
- 238000002347 injection Methods 0.000 description 2
- 239000007924 injection Substances 0.000 description 2
- 238000000691 measurement method Methods 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 239000007822 coupling agent Substances 0.000 description 1
- 238000013028 emission testing Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/08—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces
- G01N3/10—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces generated by pneumatic or hydraulic pressure
- G01N3/12—Pressure testing
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L5/00—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes
- G01L5/0047—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes measuring forces due to residual stresses
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Geophysics And Detection Of Objects (AREA)
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
Abstract
The invention discloses a novel method for testing geostress jointly by acoustic emission and differential strain, comprising the main steps: through cooperation of a differential strain test system and an acoustic emission monitoring system, the differential strain test system acquires changes of a rock sample in strain value in all directions along with time and confining pressure in real time through a data acquirer and a strain gauge attached to the surface of the rock sample; the acoustic emission test system acquires an acoustic emission signal generated due to the compressive deformation of the rock sample during a differential stress experimental process through an acoustic emission probe mounted on the surface of a differential strain confining pressure chamber and transmitting the acoustic emission signal to an acoustic emitter, the acoustic transmitter acquires a curve of change over time for acoustic emission impact times in connection with the processing of computer software and determines a moment corresponding to an acoustic emission Kessel effect point according to the obtained curve of change over time for the acoustic emission impact times; a rock sample strain value corresponding to the moment is selected as rock field status strain value, a main strain value and a main stress value are obtained by computing, and the main stress value is a field actual main stress value.
Description
Technical Field
The invention belongs to the technical field of indoor oilfield ground stress measurement, and particularly relates to a novel experimental method for testing ground stress through acoustic emission and differential strain.
Background
The earth stress, as an objectively existing natural force in the formation, affects the overall process of oil and gas exploration and development. In the drilling and development of the oil and gas field, the magnitude and the direction of the ground stress of an oil and gas reservoir area are mastered, powerful guarantee can be provided for the arrangement of an oil and gas field development well pattern and the density of the optimized drilling mud, and meanwhile, accidents such as leakage, blowout, collapse, blocking and the like can be reduced or avoided. Therefore, the method is crucial to the measurement and calculation of the magnitude and direction of the stress of the oil field. At present, the measurement of the stress of the oil field mainly comprises a data analysis method, a perforated stress measurement method and a core analysis method. The data analysis method is characterized in that the distribution rule of a large-scale ground stress field is qualitatively given through analyzing the data of river transition, plate action, topographic relief, geological structure and the like, and the fine stress field research is difficult to be carried out; the measurement of the pore stress, such as the measurement of hydraulic fracture stress, the measurement of borehole wall collapse stress azimuth and the like, can provide a relatively accurate measurement result of the ground stress, but the measurement cost is high, and the measurement is not suitable for being carried out in a large range; the core analysis method is a derivative of a porous stress measurement method, generally performs measurement indoors, does not need a large amount of field equipment and personnel, and is widely applied.
The differential strain is a method for determining the field three-dimensional stress direction and stress value through an indoor core experiment, and belongs to the field of a core analysis method. In the traditional differential strain experiment process, after the differential strain experiment sampling, a triaxial experiment sample needs to be drilled on the rest columnar drilling rock core. And (3) putting a triaxial test sample into a triaxial test machine according to the requirement of a triaxial strength test, carrying out isobaric test on the elastic wave velocity of the rock in the confining pressure process, finding out confining pressure when the measured wave velocity is close to the field wave velocity, and taking the confining pressure as the target confining pressure of a differential strain test. Traditional differential strain experiment needs the cooperation of triaxial compression experimental apparatus and sound wave test experimental apparatus, and the experiment is with high costs, requires highly to operating personnel, and the experiment operation is complicated, and the experimental result receives the influence of equipment precision and artificial operation factor easily, needs to improve urgently. Therefore, in order to carry out indoor ground stress measurement experiments more simply and accurately, the novel experimental method for testing ground stress through acoustic emission and differential strain combination is invented.
Disclosure of Invention
In order to solve the problems in the existing differential strain experiment, the invention provides a novel method for testing the crustal stress by combining acoustic emission and differential strain, and simple and accurate measurement of the crustal stress is realized by improving the traditional differential strain experiment.
Therefore, the technical scheme adopted by the invention is as follows:
a new method for jointly testing the ground stress through acoustic emission and differential strain needs a differential strain testing system and an acoustic emission testing system to be matched, wherein the differential strain testing system collects the change conditions of strain values of the rock test piece in all directions along with time and confining pressure in real time through a data collector and a strain gauge adhered to the surface of the rock test piece; the acoustic emission monitoring system and the differential strain testing system work simultaneously, an acoustic emission probe installed on the surface of the differential strain confining pressure bin is mainly used for collecting an acoustic emission signal generated by compression deformation of a rock test piece in the differential strain experiment process in real time and transmitting the acoustic emission signal to an acoustic emission instrument, the acoustic emission instrument is processed by combining computer software to obtain a change curve of an acoustic emission impact number along with time, and the time corresponding to an acoustic emission Kesephel effect point is determined. After the moment corresponding to the Kaiser effect point is determined, the rock test piece strain value at the same moment is selected as the rock field state strain value, and a main strain value and a main stress value are obtained through calculation, wherein the main stress value is the field actual main stress size.
The differential strain testing system comprises a confining pressure bin, a strain gauge and a data acquisition unit.
The strain gauges are all adhered to the surface of the rock test piece, and the data acquisition unit is connected with the strain gauges and the computer at the same time.
The acoustic emission monitoring system comprises an acoustic emission instrument, an amplifier and an acoustic emission probe, wherein the acoustic emission probe is connected with the amplifier and the acoustic emission instrument through a data line.
As mentioned above, the acoustic emission probe is arranged on the surface of the confined pressure chamber after the contact surface is coated with the coupling agent.
As mentioned above, the differential strain test system and the acoustic emission monitoring system must be started and ended simultaneously during the experiment, and the whole experiment process is kept in the starting state.
The working mode of the novel method for testing the ground stress by the combination of the acoustic emission and the differential strain is as follows:
after the rock test piece is placed in the confining pressure bin, hydraulic oil is injected into the confining pressure bin, after the hydraulic oil is filled, an oil discharge valve of the hydraulic bin is closed, and oil injection is stopped; then, simultaneously starting a differential strain testing system and an acoustic emission monitoring system, continuously injecting oil, and acquiring the change conditions of a strain value, a confining pressure value and an acoustic emission impact number along with time in the experimental process in real time; and when the acoustic emission Kesepher effect point appears, stopping injecting oil and stopping experimental data acquisition.
Compared with the existing differential strain experiment, the invention has the characteristics and advantages that:
compared with the traditional differential strain experiment, the method does not need the cooperation of a rock triaxial compression experiment device and a sound wave test experiment device, namely, the maximum value of confining pressure required to be applied in the differential strain experiment is determined through a wave velocity test experiment of the rock in a triaxial compression stress state, the requirement on experimental equipment is lower, and the experimental cost is low; meanwhile, the experimental process is simpler, and only the acoustic emission monitoring device is needed to be matched, namely, the field state strain value of the rock is determined by monitoring the acoustic emission signal generated by the rock test piece in the isotropic compression process, so that the operation is simpler, the influence of manual operation in the original differential strain experiment on the experimental result is avoided, and the experimental result is more accurate; more importantly, the method for judging the strain state of the rock test piece by the acoustic emission Kaiser effect is more direct, more accurate and easy to popularize in a large range.
Drawings
The drawings are only for purposes of illustrating and explaining the present invention and are not to be construed as limiting the scope of the present invention. Wherein,
FIG. 1 is a flow chart of the operation of the novel method of the present invention for joint testing of ground stress by acoustic emission and differential strain;
the reference numbers illustrate:
1. a confining pressure bin; 2. an acoustic emission probe; 3. an acoustic emission instrument; 4. a computer; 5. a data acquisition unit; 6. a rock test piece; 7. a strain gauge.
Detailed Description
In order to more clearly understand the technical features, objects, and effects of the present invention, embodiments of the present invention will now be described with reference to the accompanying drawings.
As shown in FIG. 1, the present invention provides a new method for testing ground stress by acoustic emission and differential strain, and the implementation of the method needs a differential strain testing system and an acoustic emission monitoring system to cooperate.
As shown in FIG. 1, the differential strain test system comprises a confining pressure chamber 1, a strain gauge 7 adhered to the surface of a rock test piece 6, a data acquisition unit 5, a computer 4 and a data line connecting the data acquisition unit and the data acquisition unit. The strain value of the rock test piece 6 generated under the action of the isotropic confining pressure is firstly collected by the strain gauge 7, transmitted to the data collector 5 through a data line and then transmitted to the computer 4, so that the change condition of each surface strain value of the rock test piece 6 along with time is obtained.
As shown in FIG. 1, the acoustic emission monitoring system is composed of an acoustic emission probe 2 placed on the surface of the confined chamber, an acoustic emission instrument 3, a computer 4 and a data line connecting the acoustic emission probe and the computer. The rock test piece 6 is compressed and deformed under the action of confining pressure, the generated acoustic emission signal is firstly received by the acoustic emission probe 2 and is transmitted to the acoustic emission instrument 3 through a data line, and the acoustic emission instrument 3 is combined with the computer 2 to calculate to obtain a time-varying curve of acoustic emission impact number.
The application method of the new method for jointly testing the ground stress through the acoustic emission and the differential strain specifically comprises the following steps:
step 1, adhering a strain gauge 7 to each surface of a rock test piece 6 according to the requirements of a traditional differential strain experiment, placing the rock test piece 6 at a base of a confining pressure bin, simultaneously connecting the strain gauge 7 with a data acquisition unit 5 through a data line, and connecting the data acquisition unit 5 with a computer 4;
step 2, closing the confining pressure bin 1, opening an oil discharge valve positioned at the top of the confining pressure bin 1, injecting hydraulic oil into the confining pressure bin until the confining pressure bin 1 is filled, closing the oil discharge valve, and stopping injecting oil;
step 3, connecting the acoustic emission probe 2 with an acoustic emission instrument 3 through an acoustic emission data line, connecting the acoustic emission instrument 3 with a computer 4, and placing the acoustic emission probe 2 on the upper surface of the confined pressure chamber 1;
step 4, simultaneously starting the differential strain testing system and the acoustic emission monitoring system, starting to continue injecting oil, and acquiring the strain value generated by the compression deformation of the rock test piece 6 and the change condition of the acoustic emission signal along with time and confining pressure in the experimental process in real time;
and 5, continuously observing a change curve of the acoustic emission impact number obtained in the experimental process along with time, stopping all experimental data acquisition after an acoustic emission Kaiser effect point appears, and stopping oil injection.
And 6, determining strain values of all surfaces of the rock test piece 6 acquired by the differential strain testing system at the same time according to the time when the acoustic emission Kesepher effect point appears, taking the strain values as original strain values of the rock test piece 6 in the field state, and obtaining a main strain value and a main stress value through calculation, wherein the main stress value is the actual field main stress.
The above description is only an exemplary embodiment of the present invention, and is not intended to limit the scope of the present invention. Any equivalent changes and modifications that can be made by one skilled in the art without departing from the spirit and principles of the invention should fall within the protection scope of the invention.
Claims (6)
1. A new method for jointly testing ground stress through acoustic emission and differential strain is realized by matching a differential strain testing system and an acoustic emission monitoring system, and is characterized in that:
compared with the traditional differential strain experiment, the novel method introduced by the patent does not need the cooperation of a rock triaxial compression experiment device and a sound wave test experiment device, namely, does not need the wave velocity test experiment of the rock in a triaxial compression stress state to determine the maximum value of the confining pressure required to be applied in the differential strain experiment, only needs the cooperation of an acoustic emission monitoring device, namely, determines the rock field state strain value by monitoring the acoustic emission signal generated by the rock test piece in the isotropic compression process;
the new method has the advantages of lower requirements on experimental equipment, low experimental cost, simpler experimental flow and simpler operation, avoids the influence of manual operation on the experimental result in the original differential strain experiment, ensures that the experimental result is more accurate, judges the strain state of the rock test piece by the acoustic emission Kaiser effect more directly and more accurately, and is easy to popularize in a large range.
2. The new method of joint testing of ground stress by acoustic emission and differential strain according to claim 1, characterized in that: application to the acoustic emission cather effect.
3. The new method of joint testing of ground stress by acoustic emission and differential strain according to claim 1, characterized in that: the differential strain test system comprises a confining pressure cabin, a strain gauge and a data acquisition unit, wherein the maximum pressure borne by the confining pressure cabin is 100MPa, and the pressure in the confining pressure cabin can be monitored and acquired in real time.
4. The new method of joint testing of ground stress by acoustic emission and differential strain according to claim 1, characterized in that: the acoustic emission monitoring system comprises an acoustic emission instrument, an amplifier and an acoustic emission probe, wherein the acoustic emission probe is arranged on the upper surface of the confining pressure chamber.
5. The new method of joint testing of ground stress by acoustic emission and differential strain according to claim 1, characterized in that: the differential strain testing system and the acoustic emission monitoring system must be simultaneously opened and closed in the experimental process.
6. The new method of joint testing of ground stress by acoustic emission and differential strain according to claim 1, characterized in that: the number of acoustic emission probes required is 1-2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610131570.3A CN105738215A (en) | 2016-03-09 | 2016-03-09 | Novel method for testing geostress jointly by acoustic emission and differential strain |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610131570.3A CN105738215A (en) | 2016-03-09 | 2016-03-09 | Novel method for testing geostress jointly by acoustic emission and differential strain |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN105738215A true CN105738215A (en) | 2016-07-06 |
Family
ID=56250087
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610131570.3A Pending CN105738215A (en) | 2016-03-09 | 2016-03-09 | Novel method for testing geostress jointly by acoustic emission and differential strain |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105738215A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106679871A (en) * | 2017-01-05 | 2017-05-17 | 中国石油大学(华东) | Method for obtaining actual stress value of rock under uniaxial acoustic emission by using internal friction angle |
| CN107702990A (en) * | 2017-11-06 | 2018-02-16 | 西安科技大学 | A kind of sound emission extensometer and its test method |
| CN110375917A (en) * | 2019-08-27 | 2019-10-25 | 江苏拓创科研仪器有限公司 | A kind of difference strain geostress survey device |
| CN114441302A (en) * | 2020-11-06 | 2022-05-06 | 中国石油化工股份有限公司 | Method and system for measuring true ground stress by using single-axis acoustic emission |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102954914A (en) * | 2012-10-31 | 2013-03-06 | 长江水利委员会长江科学院 | True triaxial test ultrasonic wave and acoustic emission testing system and testing method thereof |
| CN103308388A (en) * | 2013-05-27 | 2013-09-18 | 华侨大学 | Active or passive combined acoustic testing and seepage testing combined system for rock triaxial test |
| CN103344493A (en) * | 2013-03-29 | 2013-10-09 | 安徽理工大学 | Measuring method and testing device for stress of primary rock based on sound emission principle |
| CN103983302A (en) * | 2014-04-30 | 2014-08-13 | 重庆大学 | Coal seam gas adsorption and desorption deformation and deformation force dynamic test system |
-
2016
- 2016-03-09 CN CN201610131570.3A patent/CN105738215A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102954914A (en) * | 2012-10-31 | 2013-03-06 | 长江水利委员会长江科学院 | True triaxial test ultrasonic wave and acoustic emission testing system and testing method thereof |
| CN103344493A (en) * | 2013-03-29 | 2013-10-09 | 安徽理工大学 | Measuring method and testing device for stress of primary rock based on sound emission principle |
| CN103308388A (en) * | 2013-05-27 | 2013-09-18 | 华侨大学 | Active or passive combined acoustic testing and seepage testing combined system for rock triaxial test |
| CN103983302A (en) * | 2014-04-30 | 2014-08-13 | 重庆大学 | Coal seam gas adsorption and desorption deformation and deformation force dynamic test system |
Non-Patent Citations (2)
| Title |
|---|
| 葛伟凤 等: "盐膏岩 DRA-Kaiser 地应力测试方法初探", 《岩石力学与工程学报》 * |
| 谢强 等: "利用声发射法和变形率变化法联合测定地应力", 《煤炭学报》 * |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106679871A (en) * | 2017-01-05 | 2017-05-17 | 中国石油大学(华东) | Method for obtaining actual stress value of rock under uniaxial acoustic emission by using internal friction angle |
| CN107702990A (en) * | 2017-11-06 | 2018-02-16 | 西安科技大学 | A kind of sound emission extensometer and its test method |
| CN107702990B (en) * | 2017-11-06 | 2023-08-04 | 西安科技大学 | Acoustic emission extensometer and test method thereof |
| CN110375917A (en) * | 2019-08-27 | 2019-10-25 | 江苏拓创科研仪器有限公司 | A kind of difference strain geostress survey device |
| CN114441302A (en) * | 2020-11-06 | 2022-05-06 | 中国石油化工股份有限公司 | Method and system for measuring true ground stress by using single-axis acoustic emission |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4149409A (en) | Borehole stress property measuring system | |
| Ljunggren et al. | An overview of rock stress measurement methods | |
| CN103513272B (en) | A kind of microseism analog monitoring method | |
| CN105675400B (en) | Simulate the test method that roadway excavates off-load | |
| CN112345647B (en) | Surrounding rock loosening ring test method | |
| CN110907086A (en) | Three-dimensional ground stress determination method based on borehole wall surface displacement measurement | |
| CN104949868A (en) | Blasting damaged rock sample preparation and micro-macro combined damage degree determination method | |
| CN106525686B (en) | A kind of customization pulsed rock fracture in dynamic indentation imitative experimental appliance and its experimental method | |
| CN104865124A (en) | Shale brittleness index determination method based on rock stress-strain curve and ultrasonic longitudinal wave velocity | |
| CN103513280B (en) | A kind of microseism monitoring simulation system | |
| CN104990777A (en) | Impact damage rock sample preparation and assay method based on SHPB test | |
| CN105758561A (en) | Visual uniformly-distributed hydraulic fracturing ground stress measurement device and measurement method | |
| CN103868993A (en) | Method and device for acoustic discrimination of multistage yield points by rock triaxial single sample method | |
| CN105738215A (en) | Novel method for testing geostress jointly by acoustic emission and differential strain | |
| CN103806906A (en) | Rock mass/soil mass drilling in-situ test device and method | |
| CN112557499B (en) | Experimental method for influence of joints on stress wave transmission and reflection rules based on ultrasonic waves | |
| CN102305829A (en) | Rock triaxial compression acoustic emission test system | |
| CN109709214B (en) | Dynamic crack measuring device in shale in-situ conversion process | |
| CN104005747A (en) | Confining pressure hydraulic fracturing experiment device and use method thereof | |
| CN103790582A (en) | Geostress measuring device and method | |
| CN116411959A (en) | Oil-gas well fracturing test device and method for simulating real stratum environment | |
| CN107060714A (en) | Large-scale true triaxial physical model test method for researching thin interbed fracture extension rule | |
| CN112100842B (en) | Novel method for identifying abnormal region of crustal stress and measuring crustal stress in large range | |
| Zhao et al. | Acoustic emission behaviors of the Beishan granite under uniaxial and triaxial compression conditions | |
| CN202216938U (en) | Rock triaxial compression acoustic emission testing system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20160706 |
|
| WD01 | Invention patent application deemed withdrawn after publication |